Can two air compressors supply air to one pipeline?

Two air compressors can supply air to the same pipeline however, it should be reasonably configured according to the equipment type, control mode and pipeline design to ensure stable and efficient operation of the system. The following is a specific analysis:

1. feasibility analysis

1. basic conditions
   • pressure matching: The rated exhaust pressures of the two air compressors shall be consistent (e. g. 0.8MPa) to avoid equipment overload or insufficient gas supply caused by pressure difference.
   • flow superposition: If the flow rate of a single air compressor is insufficient (e.g. the gas production rate of a single air compressor is 5m & sup3;/min, demand 10m & sup3;/min), the two parallel units can superimpose the flow rate to meet the gas demand.
   • Piping compatibility: The pipe diameter needs to be large enough to reduce the pressure loss. For example, when two 10m & sup3;/min air compressors are connected in parallel, the pipe diameter is recommended to be ≥ DN80 (specific calculation is required).
2. Typical application scenarios
   • large fluctuation of gas consumption: If the gas consumption of the factory is high during the day and low at night, one air compressor can be started to meet the basic demand, and two air compressors can be operated at the same time during peak hours.
   • Standby Redundancy Design: One is used as the main use and the other is used as the backup to ensure that the system does not stop when the main equipment fails.
   • Energy saving demand: Through the variable frequency air compressor, the number of operating units is automatically adjusted according to the air consumption to reduce energy consumption.

2. Connection Mode and Control Strategy

1. Parallel connection (recommended)

• structure: The outlets of two air compressors are connected to the main pipeline after merging through the pipeline to form a parallel system.
• Advantage:
  • flow overlay, to meet the demand for large flow.
  • Can be flexible to start and stop a single equipment, adapt to the fluctuation of gas.
  • Backup redundancy to improve system reliability.
• Control mode:
  • manual control: Manually start and stop the equipment according to the gas consumption, suitable for simple scenes.
  • automatic control: Monitor the pipeline pressure through the pressure switch or PLC controller, and automatically start and stop the equipment. For example:
    • when the pressure is lower than the set value (such as 0.7MPa), start the second air compressor;
    • when the pressure is higher than the set value (such as 0.85MPa), shut down one equipment.
  • centralized control the air compressor joint control system is adopted to uniformly dispatch the operation of multiple devices and optimize energy efficiency.

2. Series connection (not recommended)

• structure: The outlet of one air compressor is connected to the inlet of the other to form a series system.
• Question:
  • pressure superposition may cause overpressure damage to downstream equipment (for example, the pressure reaches 1.6MPa after two 0.8Mpa air compressors are connected in series).
  • Increased piping complexity and maintenance costs.
• Applicable Scenarios: Only when extremely high pressure is required (such as special experiments or processes) and cannot be met by a single device, the final pressure needs to be controlled by the pressure reducing valve.

3. Key Considerations

1. equipment Synchronization
   • if the two air compressor models are different (such as a screw type, a piston type), it is necessary to ensure that the exhaust pressure and flow matching, to avoid one overload or the other idling.
   • When the frequency conversion air compressor and the fixed frequency air compressor are connected in parallel, the frequency shall be coordinated by the controller to prevent frequent start and stop.
2. Pipeline design
   • branch pipe diameter: The diameter of branch pipe at the outlet of a single air compressor shall be consistent with that of the equipment outlet, and the diameter of the main pipe after convergence shall be calculated according to the total flow (such as flow rate 15m & sup3;/min, the main pipe diameter is recommended to be ≥ DN100).
   • One-way valve: Install a check valve at the outlet of each air compressor to prevent equipment damage caused by gas backflow.
   • Drain valve: Install automatic drain valve at the low point of the pipeline to avoid condensate accumulation.
3. Maintenance and monitoring
   • regularly check the tightness of the pipeline to prevent the pressure drop caused by air leakage.
   • Install pressure gauge and flow meter to monitor the running status of the system in real time.
   • Formulate emergency plans, such as whether one equipment can quickly take over the gas supply when the other equipment fails.

4. Case Reference

• an automobile factory: Three 22kW screw air compressors are connected in parallel, and the number of operating units is automatically adjusted according to the air consumption by PLC controller, with an energy saving rate of 25%.
• a pharmaceutical enterprise: Two oil-free screw air compressors are connected in parallel to provide sterile compressed air for the clean workshop, meeting GMP requirements, and the standby redundant design ensures production continuity.

5. Summary

two air compressors can supply air to the same pipeline, but the following conditions must be met:

1. parallel connection is adopted to avoid the risk of overpressure caused by series connection;
2. equipment pressure, flow matching, reasonable control mode (priority automatic control);
3. scientific pipeline design, equipped with one-way valve, drain valve and other safety devices;
4. regular maintenance and monitoring to ensure the stable operation of the system.

Through proper configuration, two air compressors in parallel can significantly improve the flexibility, reliability and energy efficiency of air supply, which is a common solution in industrial scenarios.